Several Twitter users pointed out this might mean genuine Zionists, for whom Mensch has expressed support, are blocked from her timeline.

One suggested that this would mean exclusion for Theodor Herzl, the founder of the World Zionist Organisation and a key instigator of Jewish immigration to mandate Palestine. He died more than 40 years before the state of Israel was established, but is considered one of its founding fathers.

The gaffe follows a widely tweeted image from Mensch's feed last week, when the 43-year-old posted calling for a US attack on Iraq to stop Isis jihadists advancing and threatening minority communities.

Mensch was also left red-faced in February, naming "British Muslims" she respected, without realising one of them is a Sikh.